Michael V. Ottenlips

Publications (Showing 2 of 2)

Resolving species boundaries in a recent radiation with the Angiosperms353 probe set: the Lomatium packardiae/L. anomalum clade of the L. triternatum (Apiaceae) complex

American Journal of Botany
2021

Vol. 108, Issue 7

pp. 1217-1233

Premise

Speciation not associated with morphological shifts is challenging to detect unless molecular data are employed. Using Sanger‐sequencing approaches, the Lomatium packardiae/L. anomalum subcomplex within the larger Lomatium triternatum complex could not be resolved. Therefore, we attempt to resolve these boundaries here.

Methods

The Angiosperms353 probe set was employed to resolve the ambiguity within Lomatium triternatum species complex using 48 accessions assigned to L. packardiae, L. anomalum, or L. triternatum. In addition to exon data, 54 nuclear introns were extracted and were complete for all samples. Three approaches were used to estimate evolutionary relationships and define species boundaries: STACEY, a Bayesian coalescent‐based species tree analysis that takes incomplete lineage sorting into account; ASTRAL‐III, another coalescent‐based species tree analysis; and a concatenated approach using MrBayes. Climatic factors, morphological characters, and soil variables were measured and analyzed to provide additional support for recovered groups.

Results

The STACEY analysis recovered three major clades and seven subclades, all of which are geographically structured, and some correspond to previously named taxa. No other analysis had full agreement between recovered clades and other parameters. Climatic niche and leaflet width and length provide some predictive ability for the major clades.

Conclusions

The results suggest that these groups are in the process of incipient speciation and incomplete lineage sorting has been a major barrier to resolving boundaries within this lineage previously. These results are hypothesized through sequencing of multiple loci and analyzing data using coalescent‐based processes.

DOI:

10.1002/ajb2.1676

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Evolutionary origins of three rare alpine-endemic species of Lomatium (Apiaceae) in the Wallowa and Elkhorn mountains of Northeastern Oregon

International Journal of Plant Sciences
2020

Vol. 181, Issue 7

pp. 748-765

Premise of research. Shared ancestry and convergent/parallel evolution are the two primary causes of morphologically similar species occurring in similar climatic niches. Alpine habitats harbor a unique biodiversity that is often characterized by many convergences in life-forms, such as cushion and rosulate habits. Three species of Lomatium (L. greenmanii, L. erythrocarpum, and L. oreganum) are high-alpine specialists endemic to the Wallowa and Elkhorn Mountains of northeastern Oregon. Earlier studies suggested that two of these species might be sister taxa, but because of the prevalence of convergence in alpine habitats and recent studies that have highlighted morphological homoplasy among Lomatium species, this hypothesis warrants reconsideration. Methodology. Phylogenetic analysis of 209 individuals representing 79 taxa belonging to subfamily Apioideae (Apiaceae) was used to investigate the evolutionary origins of three alpine-endemic species of Lomatium. A principal components analysis based on BioClim variables was used to further investigate species climatic niches. Pivotal results. The three alpine-endemic species of Lomatium from northeastern Oregon represent three independent origins of alpine adaptations rather than a single or two alpine radiations, as previously suggested. Conclusions. Convergence and parallelism are especially common in alpine habitats and among Lomatium species, a finding confirmed by this study. This study unveils unpredicted phylogenetic diversity in the Wallowa and Elkhorn Mountains, which, therefore, calls for appropriate conservation measures to protect these distinct evolutionary lineages.

DOI:

10.1086/709373

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Michael V. Ottenlips | Flora of the World